The next instalment in FoAM Kernow talking with Sam Gyimah MP: Minister of State for Universities, Science, Research and Innovation via Sarah Newton MP

First actually fully cut, drilled and milled PCB - 0.5mm traces, 0.5mm endmill - a pattern matrix sensor board.

A CNC success, finally! 0.5mm milling drill, 0.135mm depth, voronoi regions rather than tracks, paper based PCB rather than fibreglass (smells better too)

I <3 cnc. Drill bit: 1mm, mill bit: 0.8mm, mill depth 0.235mm, feed: 45mm/min, track width 1mm, track clearance 1mm - with a test IC that could actually be soldered.

First attempt at CNC milling a circuit board - getting it level seems to be one of the tricks to solve.

Quick experiment with conductive threads, works better than expected

The new PCBs arrived! Precision surface mount soldering to come next by @amberfirefly - to position the sensors and connector.

@entreprecariat 'in theory there is no difference between theory and practice'

Got it working in the end, now switched to 3 multiplexers for the sensors - so we can use 3 pins to read 48 analogue photo interrupter signals for 16 virus capsid faces!

This went badly, had to desolder wrong value resistors and got the diodes the wrong way around - and then it didn't work anyway - trusted simulation too much, didn't breadboard enough.

Realised I can debug the invisible with my rubbish phone camera - new IR photo interrupter sensors for There seems to be a lot more infrared than it looks, as this is the max voltage without getting saturation interference with the detectors next to them...

Finally dispatched to pcb fab, after about 15 revisions - the simpler they are the harder they seem to be to get right :) fingers crossed...

Show older

Server run by the main developers of the project 🐘 It is not focused on any particular niche interest - everyone is welcome as long as you follow our code of conduct!